Metal working



June 7, 1960 c. A. NICHOLS ETA!- 2,939,350

METAL WORKING Filed Aug. 23, 1954 s Sheets-Sheet 1 7' hair Affamey 6 Sheets-Sheet 2 Charles A Nichols George L. Weiser Tire/r A fforney C. A. NICHOLS ETAL METAL WORKING June 7, 1960 Filed Aug. 23, 1954 June 1960 c. A. NICHOLS ETA!- METAL WORKING Filed Aug. 23, 1954 6 Sheets-Sheet 3 INVENTOR. Lfiar/es A. Nichols George L. Weiser T/jreir A Home Fig. 3

June 7, 1960 c. A. NICHOLS ETAL 2,939,350

METAL wonxmc Filed Aug. 23, 1954 e Sheets-Sheet 4 i i A o2 r 49/147,471! L 20 INVENTOR Fl 5 Charles AJVic/Ia/s George L. Weiser I00 w Their A Home June 7, 1960 c. A. NICHOLS EI'AL 2,939,350

METAL WORKING Filed Aug. 23, 1954 6 Sheets-Sheet 5 7 BY George L Weiser His Attorney June 7, 1960 c. A. NICHOLS ,9

METAL WORKING Filed Aug. 23, 1954 6 Sheets-Sheet 6 INVENTOR. Q: Charles A. Nlqhols w m George L. Welser His Afforn ey' United States Patent O METAL WORKING Charles A. Nichols, Anderson, and George L. Weiser,

Middletown, Ind., assignors to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed Aug. 23, 1954, Ser. No. 451,647

. 4 Claims. (Cl. 8025) This invention relates to metal working and is particularly concerned with gap rolling of metal parts for pro-- the invention to provide for preloading of the gap rolls foreliminating spring back and play together with a back off mechanism which permits the rolls to be re-established in their starting position after a rolling operation is complete.

In carrying out the above object, it is a further object .to provide the mountings for the rolls with means, such as eccentrics, which can be actuated to bring the rolls closer together at the initiation of the rolling step for preloading the rolls and thereby eliminating inaccuracies due to spring in the mountings, sideplay, etc., and wherein the rolls can be backed off from the other at the conclusion of the rolling operation for facilitating re-establishment of .the rolls in their initial position whereupon the preloading apparatus again may be used to initiate the next cycle of operation of the device.

Another object of the invention is to provide a gap rolling apparatus with positive means for moving the rolls" at a point remote from the pivot for the rolls for reducing spring back and bending stresses on the pivot shaft.

This object is accomplished through the use of rockers which act downwardly on the rolls with a substantially vertical component of force at all times whereby bending stresses are eliminated and wherein a more positive means for driving the rolls is provided.

In conjunction with the above objects, it is a further object to provide adjustment means for the rockers in the form ofa wedge which adjusts the driving member for the rocker upwardly or downwardly as desired to provide the desired stroke whereby micrometer adjustments of the gap rolls may be provided. In this connection it should be noted that the gap rolls driven by rockers as set forth in this invention are not self-actuating on the return stroke and for this reason, yieldable means are provided for reestablishing the gap rolls in their initial position upon completion of an operation, said yieldable means being in the form of weights, fluid operated cylinders and the like which cause the rolls to rotate in reverse direction while remaining in contact with the rockers.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein preferred embodiments of the present invention are clearly shown.

In the drawings:

Fig. 1 is a view partly in section of a gap rolling apparatus utilizing one form of rockers and return means in the initial or starting position of an operation.

Fig. 2 is a view of the apparatus shown in Fig. 1 in th extreme downwardly or final position of an operation.

Fig. 3 is an apparatus similar to the apparatus shown in Fig. 1 wherein another type of rocker is utilized, the apparatus being shown in the starting position.

Fig. 4 is a view in section of a feeding apparatus which may be used in connection with the gap rolling device shown in Figs. 1 through 3 inclusive Fig. 5 is a section taken on line 55 of Fig. 4.

Fig. 6 is a view of one type of preloading and back off apparatus using gears wherein the gap rolls are shown in the backed olf position at the start of an operation.

Fig. 7 shows the preloading and back off apparatus noted in Fig. 6 wherein the rolls are in the preloaded position and Fig. 8 is a modification of the preloading and back oif mechanism wherein levers and hydraulic cylinders are used to accomplish the desired result wherein the rolls are shown in the preloaded position in full lines and in the backed off position in dot-and-dash lines.

The gap rolling apparatus has been used extensively for metal working functions wherein contours are to be formed on metal parts. This gap rolling has been used quite successfully in the manufacture of compressor blades for axial flow gas turbines and the like. In copending applications 299,316 filed July 17, 1952, now Patent 2,781,678, 305,473 filed Aug. 20, 1952, now Patent 2,766,645, and 305,474 filed Aug. 20, 1952, now Patent 2,773,404, all assigned to the assignee of the present invention, several gap rolling devices have been disclosed which produce highly satisfactory results. In all of the aforementioned disclosures, gap rolls are shown which are driven by means of stepped pushers, gears and the like wherein the actuating mechanism and supporting structures are subject to bending which in many cases reduces the accuracy of the rolling operation. It is to be understood that these conditions arise for the most part when heavy sections are being rolled and when small parts are being formed that the problems in many cases do not exist. However, the apparatus as disclosed and claimed herein, while being particularly applicable to heavy duty applications, will function equally well in connection with small parts. 1

In order to reduce the effect of stress on the positioning members and gears used in the rotation of the gap rolls, we have devised an entirely new apparatus which utilizes rockers in place of gears wherein the forces applied to the rolls are maintained substantially vertical in nature whereby bending stresses are eliminated and more positive rolling operation is accomplished. We have also provided means in the present apparatus for reducing spring back of parts of the apparatus due to actual springiness in the components thereof and the play of the journale'd portions thereof. This is accomplished by preloading the gap rolls, that is to say, moving them toward one another in the horizontal plane, whereby spring back of the component parts, play in the journals, etc., is taken up by the preloading prior to the time that the actual gap rolling is operative. It is apparent that after the gap rolling operation is complete, in order to re-establish the rolls in their initial position, that the preload must be removed and for this reason a back off mechanism is also provided which operates at the end of each rolling operation in timed relation to the position of the rolls. It is understood-that the preloading also may be automatically controlled whereby the rolls are properly conditioned prior to the initiation of the gap rolling step, all of such automatic functions being well known in the art.

Referring to the drawings and specifically to Fig. l, a pair of gap rolls 20 and 22 are shown which are journaled on shafts Hand 26 respectively. The rolls have the desired contour at their rolling faces 28 and 30, respectively for forming a desired part. rolled is placed between the faces '28 and 30 and the rolls are pressed downwardly to draw the part therebetween and to contoun the metal thereof, this being accomplished as the rol'ls and ZZ-turn o ii'fl jeirjournalsupon shafte 2'4and2y6; if 1, 1f The part to be roll'ed is preferably held in afixturep32 which is yielda'hlyrmounted and which 'will m'ove downwardlyas thefroll'ing progresses.. inorder to'turn the rolls downwardly, a pair of rockers 34 and 316 areutilized which fit into sockets 38' and 49 respectively of the rolls 20 and 22. These rockers pivot in 'the'sookets as they are forced downwardly. In this connection, the upper end .of -rockers 34 and 36 are provided with sectorgearsA-Z and 144'respectively which engage ara' k '36 which is carried by-a platen 48mounted on the movable or ram member 50 of a press. The gap rolls are carried on afixture '52 which rests 'on the stationary or bottom platen '54 of the sam press. Thus, as the ram of thepress'rnoves't-he platen 50 dow-nwardl the rockers 34 and 36'mc-ve downwardly in a generally vertical direction to actually push the rolls 20 and 22 downwardly causing thern'to rotate about their axes whereby any part held therebetween' is formed during the movement of the rolls. At the end of the operation, as noted in Fig. 2, the rolls are in a downwardly rotated position whereupon the press, is reversed in direction and the rolls forcethe rockers upwardly due to weights 6 and 58 attached to cables "60 and 62 that are mounted'on' the rolls 20 and22 respectively. In place of weights, other yieldable devices may begprovided such as pneumatic orhydraulic cylinders, etc. j It will he noted that during the rolling operation the rockers always act in a generally vertical direction Whereby; the components of force moving against the gap rolls to drive them around their axes aresfibstantiall-yvfltical. This causes mostof the stress in the apparatus to bein shear rather than bending stresses as have heretofore been apparent: Thus, it is obvious that less spring'back is obtairied whereby the accuracy of the entire operation is improved. l In o'rder to adjust the movernent ofthe gap rolls through the rockers 34 and 36, the rack 46is' adjustable upwardly or downwardly relative to the platen 48 by means of wedge 'rhen'ibersone' of which is shown, at 64- Asirnilar wedge-(not shown) is 'provided:fortheotherlrack. 'The wedges 64 may be moved inwardly or outwardly to "change'the distance of the racks from the platen 50' whereby adjustment may be accomplished. After the wedges are in the desired position, they may be fixed 'by means of locking members, not shown.

Fig. 3 shows a modification of the rockers shown in Figs. 1 and 2. In Fig. 3-gap rolls 20 and 22 are similar in all respects to those shown in Figs. 1 and 2 and includes sockets 3'8 and 40 therein to receive the rounded ends of a pair of rockers 66 and 68. The rockers 66 and '68 are similar in most respects to the rockers 3-4 and 36 except at their upper ends they do not include sector gears but rather two rounded and spaced proturbercanes 70 and 72 and 74 and 76 respectively. These protuberances are designed to fit into sockets 78, '80, '82 and 84,

' respectively, carried by a fixture 86 which is carried by the movingplaten 50 of'the punch press. It is apparent that as the ram moves the platen 50 downwardly that the rockers pivot in the sockets 78 and 84 with generally'ver- 'tical components of force acting upon the rolls 26 and 22 until such time that the protuberances 72 and 74 seat in sockets 80 and 82 respectively whereupon the rolling operation is generally complete. If further downward movement isdesired, the rockers 66 and'68 will then pivot on protuberances Hand 74 causing the protuberances 70 and 7 6 to rockout of their sockets. In any event, the specific action of the device is substantially similar to that shown in Figs. 1 and 2. Also, adjustment'of the maybe accomplished through wedge member 'SS -Which In practice, the part to be may be driven inwardly or outwardly to vary the distance, a similar wedge being provided for the other rocker.

A section through the holding fixture is shown in Fig. 4 wherein a pair of spring fingers, one of which is shown at 89, grip a metal blank '90 which is fed down a slideway 92 by means of a pusher 94. This blank 90 is forced downwardly into engag'enient'iwith a hardened block or positioning member 95 made of hardened steel, carbaloy,

C etc. This block is replaceable as noted in Figs. 1 and 3 socket carrying fixture 86 with respect to the platen 50 i andis quite important in the positioning of thepart to be rolled. The contour of one of the gap rolls is shown in Fig. 4 at 22. The holding fixture 32 carrying the fingers 89, noted in Fig. 4, is yieldably mounted so that as the gap rolls turn, the fixture 32 and the blank '90 move downwardly against yieldable means such as hydraulic cylinders, not shown, limited by the movement of the sliding member 98 in slideway 100. During this movement the blank is rolled between the gap rolls in the desired contour. .Spring 102 is shown as diagrammatically representing yieldab'le' means for rc-establishing position of the As previously discussed, the springiness in portions of the apparatus, together with play in the, journals thereof, causes inaccuracies in the rolling operation. In order to overcome. these difiiculties, we have provided preloading means for taking up springiness, play, etc. prior to the initiation of the rolling operation. This is accomplished by mounting the gap rolls 20 and 22 eccentrically as at .104 and 106. Adjustments for the eccentrics are carried by ofiset journals in gears 108 andllt). The gears 103 and 110 engage respectively with worms 112 and .114 which are driven through gears'116, 118, etc. Thus, at the initiation of the operation, the gear 118 is caused to turn which initiates action of the gear train involving gear 116, worms 112 and 114 and gears 1'08 and 110. Turning of gears 108 and 110 in one direction causes the eccentric journals 104 and 106 of gap rolls 20 22 to move towards one another which causes "the gap rolls to meet and to become preloaded. In other words, sufiicient force is provided to take up'the springiness andplay in the rolling system. This position of the gears is maintained throughout the rolling operation. It is apparent that it would be diflicult to reestablish the rolls at'the conclusion of the rolling operation to their original position i'f-the 'preload were notremoved. For this purpose,

the' gear 118' is rotated'in the opposite direction which causes the eccentric journals 104 and106 to move, in the oppositedirection, causing the rolls 20 and 22 to likewise move aWay-from'one' another whereupon they may bebroug'ht to theiroriginal or starting position as noted i11-Flg.-6. At this point the preloading as noted in' Fig. 7 is again carried out, preparatoryto the initiation of the next rolling step; 7 5 a i Another method and apparatus for accomplishing :preloading and backingofl of the rolls is shown in Fig. 8 wherein a pair {of lever members 122 and 1 24 are provided for rolls 20 and 22 respectively, which lever memhers carry journals 126 and 128 thereon; the lever mem- Y bers 122 and l24 are actuated by pneurnatic'or hydraulic cylinders 130..1and 134 respectively through piston members 136:a nd-138 When it is desired to'preload, the rolls as i'shown in Fig. 8 in full lines, the pistons 1'36 and 138 "are 'iniretracted position. When it-is 'desired to back off then'olls as shown in dot-and-dash lines in Fig.8 the pistonmembers are moved outwardlyof the cylinders and 134 respectively. It is apparent thatiinso doing, the levers 7122.:and i24'are caused to rotate which in turn rotates-the journals 126 and 128 which move therolls towardror'away from :one another-as the case may rho.-

The particulardesign of the apparatus makes the :use of the preloadingand back-0E additions possible-' Si-nce the rolls are actuated by rockers, slight ;lateral:movenient thereoflwhich is necessary in the preloading 'an'd ibECk .off

the related portionsof the machine. Itis :apparentj-that on a hack and gear type gap roll, the possibility of disengagement of the gears upon back-01f and misalignment thereof upon preload would present problems that are not apparent with the rockers which merely move with the rolls and remain in operative positions therewith at all times.

The shifting lateral movement of the rolls is limited at all times to a movement which will not cause disengagement of the protuberances of the rockers from the several sockets. In this manner the device is always in operative condition regardless of the position of the preloading and back-off mechanism. It is apparent that if the shifting movement is not limited and predetermined that the rockers could become disengaged. In this same connection it is understood that the terminology of initial or normal position of the rolls is the unloaded position as opposed to the loade' or working position when the rolls are in engagement with a predetermined force applied sufiicient to take up play and spring in the several parts. This terminology is used merely for convenience and is not to be considered a limitation. The main feature being that the rolls are laterally shiftable through a limited and'predetermined range of movement and may be brought into engagement with one another under a selected and predetermined force.

The apparatus as disclosed herein has been found to substantially eliminate many of the inaccuracies heretofore apparent in gap rolling operations and particularly in gap rolling operations of heavy stock. In this connection, it is understood that the part to be gap rolled may be either a :blank of metal or may be a blank that has been previously preformed, as by coining, to an approximate shape. Similarly, the product of an apparatus may be coined after gap rolling if desired although we have found that such expedients are usually unnecessary due to the high degree of accuracy of parts rolled on a gap rolling apparatus as disclosed herein.

It is also to be understood that twisting of the part being gap rolled maybe also accomplished in the present apparatus if a twisting fixture is used in place of the holding fixture noted herein. One type of twisting fixture is disclosed in copending application 270,074, filed February 5, 1952 (now under order of secrecy), and assigned to the assignee herein. In other words, the preloading and backing ofi of the rolls and the use of rocker members as actuating means therefor may be used in connection with any gap rolling operation wherein a high degree of accuracy is desired.

It is also manifest that the expedients shown may be varied widely as is well known in the mechanical arts; for example, in place of weights, cylinders, etc., springs may be substituted providing said springs will produce the results set forth. Further, the rolls may be shifted in any way, for example, the entire support for the roll journal may be shifted although the apparatus as de scribed provides the most facile structure. In other words, the specific instrumentalities set forth herein are not to be limiting providing the results are obtained, namely, preloading of the rolls to eliminate spring back and play, etc., backing off of the rolls to increase the efficiency of the device and vertical component actuation of the rolls through the use of rockers to further eliminate spring back and to reduce breakage and injury of the apparatus due to bending.

While the forms of embodiment of the invention as herein disclosed constitute preferred forms, it is to be understood that other forms might be adopted, as may come within the scope of the claims which follow.

What is claimed is as follows:

1. A gap rolling apparatus, comprising; a pair of rotatably mounted opposed and mating gap rolls each including a journal and each of said rolls including a socket at a surface thereof adjacent and spaced from the mating surface thereof, a pair of rockers each including a rounded protuberance adapted to fit within one of said sockets, and means cooperating with the opposite end of said rockers for causing said rockers to press downward- 1y into said sockets for causing the gap rolls to rotate to,- wards one another, said rockers applying force in a generally vertical direction during rotational movement of said gap rolls, means cooperating with the gap rolls for returning the rolls to their original position upon cessation of force applied to said rockers, said rockers being substantially triangular in shape and having a rounded protuberance at each corner of the triangle, and including means associated with the means for applying force having spaced sockets therein adapted to accommodate first one of the protuberances opposed to the protuberance which engages the socket of the gap roll and then the second protuberance as the gap roll is rotated through force applied to the rockers.

' 2. The apparatus claimed in claim 1 including means eifective only upon rotation of said rolls for laterally shifting the rolls on their journals for causing the rolls to move toward one another through a predetermined range of movement in one direction into engagement with one another for preloading the rolls with a predetermined load whereby spring-back and play is eliminated in the subsequent action of the rolls, said means being reversible for causing said rolls to move away from one another upon movement in the opposite direction upon conclusion of a gap rolling operation thereof to their normal positions.

3. The apparatus as claimed in claim 2 wherein the means for shifting the rolls at their journals includes gearing for rotating eccentric journal supports.

4. The apparatus as claimed in claim 2 wherein the means for shifting the rolls at their journals includes eccentrically mounted levers including bearings for said journals.

References Cited in the file of this patent UNITED STATES PATENTS 315,170 Russell Apr. 7, 1885 600,734 Martin Mar, 15, 1898 741,085 Webb Oct. 13, 1903 908,493 Pierce Jan. 5, 1909 1,740,934 Raymond Dec. 24, 1929 1,841,920 Smith Jan. 19, 1932 2,118,224 Pearson May 24, 1938 2,654,277 Hedlund Oct. 6, 1953 2,674,222 Messinger et al. Apr. 6, 1954 2,766,645 Nichols et al. Oct. 16, 1956 2,774,263 Leufven Dec. 18, 1956 FOREIGN PATENTS 347,325 France Dec. 30, 1904 496,191 France July 26, 1919 227,219 Great Britain Jan. 15, 1925 605,660 France Feb. 20, 1926 

